In the past, efforts to upgrade hot rolling mills or their processes have been hampered by a lack of meaningful engineering feedback data. Attempts to collect product thickness and temperature profile data were restricted by the unavailability of highly sensitive and accurate non-contacting sensors. Normally, product thickness data (or roll gap) is obtained from a dial readout coupled to the upper roll lifter screw spindles. Such readings, however, are not very reliable because spindle nut backlash and frame springback conditions are not taken into consideration. Similar inaccurate methods and devices are generally used to determine the temperature of the rolled product.
Additionally, obtaining accurate roll gap and product temperature data in real time is important if the rolling process is to react to subtle changes in the operating conditions. Real time data also enables an operator to reduce the occurrence of and/or to prevent product loss situations. Another benefit of such fast accurate data is the ability to maintain high levels of product quality and control. Obviously, should the rolling process be operated in accordance with inaccurate or delayed data, manufacturing efficiency suffers while product loss increases. In essence, the knowledge gained by accurate, real-time data should provide a deeper insight into the mechanics of the rolling process. It should also lay the groundwork for optimized pack designs through improved calculational methods and with less reliance on trial and error practices.
Preferably, the selected sensors have to be of the non-contacting variety in order to eliminate premature wear. For maximum reliability, they also need to be installed in locations away from radiant heat exposure as well as being shielded against mechanical damage. Such locations, however, still have to satisfy the specific measuring range, signal resolutions, and response time requirements of each unit to guarantee overall system performance.
The recent introduction of laser shadow and infrared thermometry gages seem to be suited to these requirements. Consequently their integration into a structurally and thermally stable instrumentation platform is desired. This arrangement would make it possible to (a) measure side-to-side positional changes of the upper height-adjustable roll, and (b) record the lengthwise temperature profiles of the incoming and exiting rolled product at a level of accuracy heretofore never achieved. The instrumentation platform must also be vertically retractable so that the inside of the roll mill is readily accessible for roll change and routine maintence work.
Ideally, the data collected would be fed into a computerized data collection system from where it can be readily retrieved for subsequent data analysis. Once a sufficiently large control data base has been developed, the system could then be fine-tuned to recognize subtle changes in operating conditions in time to prevent product loss situations.
Consequently, it is an object of this invention to provide a rolling mill user with means for obtaining accurate process data in real time. A further object of this invention is to provide the capability of quickly retrieving data from a computerized data base. Another object of this invention is the ability to quickly identify and report discrepant process conditions. A still further object is the capability of instantly checking the rolling mill alignment, roll gap, and temperature of the product. Another object is the ability to quickly reset the mill between passes and to provide vertical clearance to ease roll changes and maintenance work. Still another object is to provide a structurally and thermally stable instrumentation platform. These and other objects of this invention will become apparent upon a reading of the text.